You'll have to go back more than four hundred years before the Reformation to see that it was the Roman Catholic church which broke this so-called unity when they went into schism with the Greek Orthodox over the very doctrines you are proudly extolling - papal primacy being one of the biggies. They don't accept Purgatory, either, and see that as just another example of Rome's novel doctrines that were not believed always by everyone and everywhere.
The Scriptures were given to us so that we could have an objective AND authoritative resource to know truth from error. The Roman Catholic church is NOT the authority.
The Catholics even deny the words of their own early church fathers which claimed sola scriptura. So they have even broken away from them.